This invention relates to an irrigation system and, more particularly, to an improved apparatus for sequentially irrigating a plurality of areas or basins, automatically stopping the flow of water to an area when that area has received sufficient irrigation and redirecting the flow of water to another area.
Irrigation systems have been used for many years to provide plants and trees with water at various times during their growing cycle. For example, it has been common practice to provide plants and trees with water by means of irrigation ditches, hoses, sprayers, pipes and other types of apparatus. However, in certain situations, such as in orchards where the terrain is uneven, water will run from the high ground to the low. In such cases, the low lying trees may receive more water than those on higher ground.
In other cases, where the cost of water is relatively high it is desirable to control the amount of water provided for each area and to avoid wasting water by providing additional water to some plants in order to adequately water others or by leaving the water on for too long a period.
The above problems have been overcome to a degree by irrigation systems having a plurality of valves with each valve connected by means of pipes to a pressurized source of water. For example, the U.S. patents of Rodieck, U.S. Pat. Nos. 3,797,253 and 4,014,361, disclose systems wherein each item to be watered is provided with a well around its base and a separate valve within each of the wells. In such systems, one or more risers may be provided in order to force each valve that has been closed by the water reaching a preselected height in the well and to remain closed for as long as there is water pressure applied to the system. Such systems also include means to prevent the flow of water to a second valve until such time that a first area has been provided with a predetermined volume of water.
The present invention contemplates an improved irrigation system of the type disclosed by the Rodieck patents, but having spring biasing means for assisting in the opening of one outlet and the closure of another. It is presently believed that the improved irrigation systems disclosed herein will be more reliable in operation, minimize the likelihood that a gate member will become stuck in a first position and thus fail to turn off a valve, and will have a more rapid trigger action and thus provide a more accurate determination of the amount of water provided to a selected area. In addition, it is presently believed that the system disclosed herein may be readily and economically manufactured, will be relatively free of maintenance and simple to operate.
The improved irrigation system disclosed herein also includes means, so that, an individual can manually select areas for additional watering without using a complete watering cycle.